In order to rout bevels and mitres at an angle, various designs have been proposed in the prior art. One example is found in Spielman, P., The New Router Handbook (New York: Sterling Publishing Co., 1993) at p. 164. In illus. 12-33 on p. 164, a router bracket is shown which can hold a router motor unit while it is tilted as much as 45.degree.. As shown in illus. 12-35 on p. 164 of Spielman, the tilted router bit can carve grooves having various profiles into the surface of a workpiece. However, the range of angles which can be cut using the device shown on p. 164 of Spielman, is limited, the router unit being unable to tilt beyond 45.degree.. In addition, the router bracket device shown on p. 164 of Spielman is not suited for routing bevels and mitres onto the sides or ends of boards, since most of the weight is at one end of the square plywood base, and that end would have to be overhanging the edge of the workpiece which is to be routed. Rather, it is intended for routing an angled groove across the middle of a flat surface.
In U.S. Pat. No. 4,977,938 (Greeson), a cutting guide for use with a hand-held router is shown, the cutting guide having a guide fence 50 which pivots about a base 20. The guide fence 50 of the cutting guide disclosed in Greeson '938 has a flanged portion 56 which butts against the edge of the workpiece being cut. By using this flanged portion 56 to position the router bit, it is assumed that the edge of the workpiece is straight and true. However, if this is not the case, the router bit will follow any curvature or imperfection along the workpiece edge. In addition, the cutting guide shown in Greeson '938 has a pivoting hinge 54 which is located adjacent to the flanged portion 56 of the guide fence 50. As shown in FIGS. 6 and 7 of Greeson '938, due to the location of the pivoting hinge 54, only the side of the router bit is used for bevelling or chamfering the underside edge of the workpiece 90. This has a tendency of compromising the edge of the workpiece 90 which is used as a reference by the flanged portion 56.
Greeson '938 also discloses a device having an adjustment means for adjusting the lateral position of the router on the top surface. This adjustment is used for finally adjusting the depth of the bevel or chamfer cuts into the edge of the workpiece. However, the speed of adjustment is quite slow, being limited by the travel over the thread of positioning adjustment screw 32 as it is turned. Additionally, the accuracy and reliability of using this method to control the depth of the cut when routing a bevel or chamfer would be inferior to using the blade depth control on the router itself for this purpose.
A further disadvantage in Greeson '938 is that it relies upon operator skill and care to maintain the guide fence 50 in position.